


Barter System

by brbsoulnomming



Category: Sherlock (TV)
Genre: Fluff, M/M, Sharing Clothes, Written pre-Series 2, semi-angst
Language: English
Status: Completed
Published: 2013-10-22
Updated: 2013-10-22
Packaged: 2017-12-30 03:41:11
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,982
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1013660
Author URL: https://archiveofourown.org/users/brbsoulnomming/pseuds/brbsoulnomming
Summary: <blockquote class="userstuff">
              <p>Written for <a href="http://sherlockbbc-fic.livejournal.com/5880.html?thread=21077496#t21077496">a prompt</a> on the Sherlock BBC prompting meme at livejournal: <br/> <br/><i>I'd love something about Sherlock&John's clothing barter system in this verse! Bring on the "Sherlock wearing John's sweaters" fics!</i></p><p>Or, Sherlock and John form a bartering system. Well, Sherlock does, anyway.</p>
            </blockquote>





	Barter System

The first time John notices Sherlock wearing one of his tee-shirts, he’s surprised. Not that Sherlock would invade John’s privacy and take whatever he liked for his own use, of course, John’s gotten used to that, irritating though it is. No, what surprises him is that it’s John’s _clothes_ that Sherlock has decided to help himself to. And not to perform some kind of experiment on the melting point of cotton tee-shirts worn by ex-army doctors or something, just to _wear_.

It’s, well, it’s kind of cute. John has to hide a wince at that thought, because that’s not really the kind of thought you should be having about your flatmate, is it, finding the fact that he’s stolen an item of your clothing and is wearing it around cute? And really, there’s a million reasons Sherlock could’ve decided to wear his shirt. For all John knows, it _could_ be some kind of experiment. Comparing fibre textures and their affect on skin, maybe, or maybe the experiment is just to see John’s reaction.

Despite that, there’s something about seeing Sherlock in John’s tee-shirt (inside out, as though Sherlock had just picked it up off the floor in passing, put it on absently, as is), along with Sherlock’s own pyjama bottoms and silk dressing gown, and somehow _not_ looking out of place, that makes John smile. 

John wants to ask him why, why Sherlock’s decided that taking the shirt John slept in last night and wearing it around the flat was a good idea. If there’s some secret purpose that John’s not getting, or if it’s just because Sherlock _wants_ to wear it. He imagines it’s a little bit of both, but likely more of the former. He suspects asking “why” will get him an answer something along the lines of, “I’m wearing your night-shirt for science, John, obviously,” but he’s going to ask anyway. John suspects they should also have a talk about privacy and borrowing things without asking again. 

But Sherlock’s in one of his moods, frustrated and irritable from boredom, and he lashes out, picking little, meaningless arguments that add up and leave John’s earlier warm affection muddled under annoyance. 

There’s no talking to Sherlock when he’s like this, John knows. He gives up trying when Sherlock rambles about John inflicting his opinions on people and flops dramatically back on the sofa, curling away from him in a pouty ball. There’s an air of tension about him; he’s waiting for something. For John to pursue the subject further, most likely, or to change the subject and try to engage him in another way. So Sherlock can turn that into an argument as well, no doubt, which means asking Sherlock about anything is off the table. 

So he leaves (and considers his suspicions confirmed when Sherlock asks where he’s going, sounding disgruntled), and then there are explosions and time limits and John forgets all about the stolen tee-shirt. 

Until the second time, months later. 

John gets home after working a shift at the surgery (covering for another doctor who’s got the flu) and Sherlock’s at the kitchen table. Petri dishes are lined up in neat rows along the table’s surface, and there’s one under the microscope that Sherlock’s leaning over, long fingers skilfully manipulating the dials on the sides of the instrument. 

“Finding anything interesting?” John asks, closing the door and hanging up his coat. 

“Don’t know yet,” Sherlock replies, carefully setting aside one dish and replacing it with another.

He sounds distracted, but not annoyed at the disruption, so John wanders into the kitchen to take a closer look. “Is it for a case, or just for-” He cuts off as he realizes what Sherlock’s wearing. “Is that my jumper?” 

Sherlock doesn’t answer, instead frowning into the microscope and making a few notes on a pad of paper next to him. 

“I said – is that my jumper?” John repeats. 

“I heard,” Sherlock replies without looking up. “I assumed a reply was unnecessary, as your eyes are perfectly functional and the answer is obvious.”

Obvious. All right, it is a bit obvious; Sherlock is quite clearly wearing John’s oatmeal-coloured jumper. And he doesn’t seem to be wearing anything under it, considering the glimpse of collarbone revealed by slightly too-baggy neckline and pale forearms bared by too-short sleeves. But John’d been looking for an explanation, not pointing out the obvious. 

“Why are you wearing my jumper?” John asks.

“Because it’s cold,” Sherlock says, sounding bored. “The radiator’s not working again and there’s a draft coming from the kitchen window; I suggest putting on one yourself.” 

John stares at him, wondering if he’s being deliberately obtuse or if he’s just actually misunderstanding what John’s asking. With Sherlock, both are likely. “But why _my_ jumper? You’ve got your own coat.” 

“I like the sleeves,” Sherlock says, holding up both forearms. “Perfect length, no need to try and push them back. The cuffs of my coat are always in the way.”

John opens his mouth to reply, then closes it again. He tries to be mad, because, really, that jumper had been hanging over the back of the chair in John’s room, which means Sherlock’s gone in his room while he was out to take his things. But, just like with the tee-shirt, there’s something almost charming about watching Sherlock doing experiments in John’s jumper. 

He gives up trying to be angry when he loses a battle with a smile, and shakes his head. “Fine. Don’t get anything on it that won’t come out,” he warns, then adds, “And if you _do_ get something on it, don’t ever tell me what it was.”

“Cultures, John, highly unlikely there will be spilling,” Sherlock replies. 

The third time, it’s another jumper. When John comes home with the shopping, Sherlock is sprawled out on the sofa. Upside down, with his feet braced against the wall, head hanging a few inches above the floor, and wearing his pyjama bottoms and John’s stripy jumper. 

“How long have you been like that?” John asks, going to put the shopping away. 

“Not long,” Sherlock says. 

“Yeah, well, sit up, would you?” John asks. “Bad for blood circulation.”

There’s the creaking of sofa cushions as Sherlock moves, surprisingly without comment. John finishes putting things away in the kitchen, then returns to the living room. Sherlock’s on his laptop now, and John sits on the sofa next to him, switching on the TV. 

“Is this going to be a thing now?” John asks, eying his jumper. “You stealing my clothes whenever you feel like?”

Sherlock looks offended. “I’m not _stealing_ them, John. We have a barter system.”

John raises an eyebrow. “You realize that a barter system requires both parties to be aware, and making use, of it?” 

Sherlock frowns. “Of course. When I wore your tee-shirt after you returned my socks, I assumed your silence was acceptance. You said my use of your jumper was fine, and afterwards you returned one of my tee-shirts, freshly laundered.” He gestures to the stripy jumper. “You are, of course, welcome to anything in my wardrobe, save my coat.” 

John stares at him. “Sherlock, I said it was fine in the same way I say you using up all the Nutella to test the properties of hazelnut and not buying more is fine. And I gave you back your clothes because you leave them all over the flat, and sometimes they get mixed in with my washing.” 

Realization briefly crosses Sherlock’s face, then his expression shuts down. “Ah. I misinterpreted. I apologize, John, I’ll-”

“It’s not quite fair, is it?” John interrupts. “If your coat’s off-limits, I should get to pick something you can’t wear as well.”

John loves this part. When understanding lights in Sherlock’s eyes, when he realizes John isn’t going to mock him or be angry at him for his mistake. When he realizes that John is going to go along with Sherlock’s mad idea (and really, as far as Sherlock goes, implementing a clothing barter system without telling him isn’t all that mad) and, more than that, John’ll probably end up _enjoying_ it. 

“What’s your off-limits decision, then?” Sherlock asks.

John has to consider that, because he can’t really think of anything he’d mind Sherlock wearing. It isn’t as though he owns much, after all. After a few moments, he settles for, “My army things.”

Sherlock tilts his head slightly. “The uniform or the camouflage?” 

“Both,” John says.

Sherlock frowns. “One article of my clothing is hardly worth two sets of yours.”

“Too bad,” John tells him, trying to resist the urge to grin and probably failing. “That’s the deal. Besides, they’re not exactly part of my normal wardrobe.” 

Sherlock seems to consider that for a moment, then he nods. “Deal.”

“Good,” John says, settling back on the sofa. “What started you on this, anyway?”

Sherlock stretches his legs out a bit, tucking his bare feet under John’s thigh. “That case we were working on with the laptop. We were walking to interview the sister. I’d forgotten my gloves, you let me wear yours, and I gave you my scarf in return. It seemed like a good system.” 

John lifts his thigh a little so Sherlock can stretch his legs out the rest of the way, then rests it on top of Sherlock’s ankle, trapping Sherlock’s feet between his thighs. Then he shifts, curling his legs up and shoving one of his feet under Sherlock’s calf, the other resting on the sofa against it. “Sometimes I wonder about your brain.” 

“Most people do,” Sherlock says, in his “I have absolutely no regard for anything you say, look at how much I don’t care” voice. 

John sighs. “I love the way your mind works. I think it’s brilliant, you know I do. Doesn’t mean I don’t wonder about it.” 

Sherlock smiles at him, almost shyly, and John grins back before turning his attention to the TV. 

It’s remarkably easy to settle into the barter system. 

John takes one of Sherlock’s scarves to do the shopping, Sherlock sleeps in one of John’s tee-shirts. Sherlock uses one of John’s knit hats, John wears a pair of Sherlock’s socks. 

Sherlock wears one of John’s jumpers every time he does one of his experiments. John falls into the habit of wearing his favourite of Sherlock’s few tee-shirts when he does his work out (a shadow of what he’d done in the army, but he’s building up slowly). 

It moves into trading permanently as well. There’s a pair of John’s gloves that fit Sherlock better, and Sherlock has a scarf that he says looks better with John’s colouring, so they switch. Sherlock has a pair of trousers that are far too short for him; he exchanges them for his favourite of John’s tee-shirts. 

John makes a bit of room in his wardrobe, for the things of Sherlock’s that he wears more often than Sherlock does but hasn’t quite traded for them officially. 

When John does laundry, only about half of it is really his. The rest of it is things that are his-but-currently Sherlock’s, or Sherlock’s-but-currently-his. 

By the time the holidays start getting close, John can’t imagine living without it. 

John gets invited to the Christmas party at the surgery (which is taking place three weeks before the actual holiday, as with half of the doctors going on holiday and the rest of them working near constant shifts to cover for them, they’ll have no time for parties closer to the actual date), and he drags Sherlock along. Mostly because while he doesn’t want to go alone, he’d feel a bit uncomfortable bringing an actual date, even though he and Sarah really are just good friends now. John’s reasonably sure most of his colleagues think he and Sherlock are actually dating, anyway, despite John’s dwindling protests otherwise. It’ll be entertaining to watch them speculating. 

He’s getting ready for it, standing in front of the mirror in his bedroom and trying to find a tie he actually _likes_ that matches the dark green shirt he’s wearing, when Sherlock calls up to him.

“John! Are you wearing your blue shirt?” Sherlock asks. 

“The light or the dark?” John asks automatically, the rolls his eyes at himself. “No, I’m not!” 

He hears footsteps starting up the stairs. 

“It won’t fit you, Sherlock, the sleeves are way too short,” John says. 

“I’ll be wearing my own jacket, no one will notice,” Sherlock says, appearing in the doorway in black trousers and his dark purple shirt, half-buttoned. 

“What happened to your own blue one?” John asks, but he’s already moving towards his wardrobe. 

“Hydrochloric acid,” Sherlock replies. “The light blue, please.” 

“Can I have your gold tie, then?” John finds his shirt and turns around. “The one with the green and-” He cuts off when he sees Sherlock holding it out to him. 

“You ironed your green shirt last night. This matches perfectly, I thought you’d be wanting it,” Sherlock says. 

John laughs, trading shirt for tie and standing back in front of his mirror to put the tie on. Behind him, Sherlock unbuttons his shirt the rest of the way, takes it off, and drops it over the back of John’s chair. 

“You know,” John says, watching Sherlock in the mirror as he puts on the blue shirt. “I’m pretty sure most of my colleagues think we’re dating.” 

Sherlock looks up from buttoning the shirt, meets John’s reflection’s gaze. “If you wanted to silence their talk, John, bringing me to this ‘social event’ won’t help.” 

“Nah. Let them talk.” John finishes adjusting his tie and turns around. “People do little else, after all.” 

Sherlock smiles at him, not the quick, fake, automatic response smile, but the slow, almost hesitant, genuinely pleased smile that’s really Sherlock’s. John looks at Sherlock, in John’s blue button-up with its too-short sleeves, and can’t do anything but smile back. 

Four hours into the party, and John’s leaning against a wall with a glass of eggnog in one hand, attention split between chatting amiably with a nurse and watching Sherlock deep in conversation with two doctors. Sherlock looks – only mildly irritated, and actually slightly interested, which is a good sign. 

One of the nurse’s friends comes over soon, and the nurse slips him her number before leaving to rejoin her friends. John pockets it absently and debates going over to Sherlock, but Sarah appears at his side before he makes a decision. 

“See you two have finally left each other’s sides long enough for me to talk to you,” she teases. 

“It’s considered rude to abandon the person you’ve brought to a party within the first few hours, you know,” John returns. 

Sarah grins and they chat about nothing, laughing and drinking eggnog. Unlike the nurse, though, Sarah catches him glancing over at Sherlock. 

“He all right over there?” Sarah asks. 

“Hmm?” John says. “Oh, yes. Fine. Should be, anyway. Probably discussing some exotic disease. I figure if anyone wouldn’t get freaked out when Sherlock starts going on about bacteria and body parts, it’d be people here.”

Sarah smiles at him. “Is that why you brought him?”

John shrugs. “Doctors love talking about their work at inappropriate times. So does Sherlock.”

“Not all doctors,” Sarah says. 

“No, just the really interesting ones. Or the really boring ones,” John adds with a laugh. “Sherlock’ll distract both of them, so I can spend my time with the pretty ones.”

Sarah rolls her eyes, then shoves him when he adds, “You’re looking very pretty tonight.”

“Shut up,” she says with a laugh. 

He smiles, then says, “Teasing aside, you do look very nice.”

“Thank you,” she says. “And you look very handsome. Is that a new tie?”

John reaches up automatically to touch the tie. “Uh, no, it’s Sherlock’s.”

“You’re wearing Sherlock’s tie?” Sarah asks. 

“Yeah, he’s got my shirt, so I’ve got his tie,” John says.

Sarah raises an eyebrow. “Oh, yeah, right, that makes perfect sense.”

“We’ve got a barter system,” John explains. 

“A barter system?” Sarah repeats. 

“Yeah, he wears something of mine, I wear something of his. So, he’s got my shirt, I’ve got his tie. Or sometimes we trade completely. He’s got a jumper of mine that might as well be his now, actually, maybe I’ll take the tie permanently and make it official,” John says.

Sarah’s grinning widely at him.

John sighs. “All right, go on, say it.”

“You two trade _clothing_ ,” Sarah says. “Do you have any idea how adorable that is?” 

“It’s not adorable, it’s _practical_ ,” John protests.

“Practical?” Sarah asks. “He’s five inches taller than you.” 

“He says he likes it,” John says. “My jumpers have short sleeves, so he doesn’t have to worry about them getting in the way when he...” John trails off when he realizes Sarah’s eyeing Sherlock consideringly. “You’re picturing him in one of my jumpers, aren’t you?”

Sarah grins at him, unapologetic. “Oh, don’t pretend you weren’t. And don’t pretend you don’t think he’s absolutely adorable in it.” 

“All right, yes, I – am not going to get caught in a trap like that.” John looks down at his cup of eggnog, which he swears is fuller than the last time he’d looked. “You’ve been refilling this, haven’t you?” 

“And what have I been refilling it with, John, my invisible bottle of eggnog?” Sarah teases. 

“If you’ve got one, how about topping me off again?” he asks. 

She laughs, and doesn’t, though whether it’s because she doesn’t have a bottle or doesn’t want to admit to having one, John doesn’t know. 

Instead, she distracts him with swapping stories of their worst patients ever (names changed to protect the not-so-innocent, of course).

“-and _then_ , not too long after the ‘I won’t stop going to work even with a broken arm’ incident, he calls me while I’m with another patient to demand I see him immediately, because he’s _dying_. He shows up with a head cold and asks my stance on mercy killings,” John says. 

“Oh, God, absolutely no way,” Sarah says through her giggles. “I refuse to believe that – hang on, was this patient _Sherlock_?”

“Can’t tell you,” John says. “Violates doctor patient con – confidential-”

“Wait, I’ve just thought of something,” Sarah interrupts. “If he’s wearing your shirt, wouldn’t it be way too short? It doesn’t look it.” 

“That one’s a bit long on me. And he’s wearing his own jacket and trousers; with those, no one’s going to notice if they can’t see his shirt sleeves under his jacket ones,” John says. 

“Mmm, true,” Sarah agrees. “Thank God for expensive tailoring, just _look_ at that arse.”

“Oh, God, I _know_ ,” John says. “You can’t even imagine what it’s like to-”

Sarah’s grinning at him again, and John snaps his mouth shut. 

“You are an evil, evil woman, Sarah Sawyer,” John tells her. 

“And you are so busted,” she says cheerfully. 

“I’m doomed, aren’t I?” he asks.

“Yeah. But at least you know it?” she offers. 

He goes to down the rest of his eggnog, but finds his cup full. “You _have_ been filling this!” 

Sarah laughs and clinks their cups together. “Cheers, John.”

John tries to be annoyed, but really he’s just entertained. “Cheers.” He drains his cup. “Now if you’ll excuse me, I’m going to go collect my – Sherlock, before we both drink so much eggnog we forget our address.” 

“You think he’s had that much?” Sarah asks, peering over at Sherlock. “His gesturing has gotten a bit more flaily.” 

“I think he doesn’t realize how much he’s had,” John says. “These are way too sweet for all the alcohol that’s in them.” 

“How do you know what’s in them?” Sarah asks. 

John grins. “I helped make them.” He kisses her on the cheek. “Happy Christmas, Sarah.” 

“Happy Christmas, John,” she calls after him as he heads over to where Sherlock’s still talking with the other two doctors (Gary and Robert, if John remembers correctly).

John stands beside him for a moment, then wraps an arm around Sherlock’s waist when one of his gestures causes him to tip a little. 

Sherlock beams at him. “John!”

“Hullo, John,” Gary greets. “Come to take your partner away?”

“I think it’s time for both of us to head home,” John says.

“That’s a shame,” Robert says. “I hope you bring him back next year.”

“He’s lying,” Sherlock mutters in John’s ear. “He never wants to see me again.” 

“Yes, he’s definitely made this year’s party interesting,” Gary says. 

“Not lying,” Sherlock whispers. “He’s reasonably intelligent.”

“I’m sure he’d love to come back,” John says. 

“Wrong,” Sherlock murmurs, lips so close to John’s ear that his breath tickles John’s skin.

John tries to stifle a giggle, and judging by the looks the other two doctors give him, fails. 

“Well, we’ll just be off, then,” John says, pulling Sherlock away. “Enjoy your holidays, gentlemen.”

Sherlock drapes his arm over John’s shoulders as they head towards the door. There’s a cup of eggnog in his other hand, and John takes it from him after he takes a long drink.

“That’s mine,” Sherlock protests. 

“You’ve had enough to drink,” John says, setting the cup down on the table as they pass. He almost misses. “And so’ve I. Come on, let’s get home.”

The next morning, John’s definitely hung over. Not enough that he feels sick or regrets drinking as much as he had, but enough that he doesn’t feel like doing anything besides lounging on the sofa and watching bad telly. He doesn’t even feel like getting dressed after he showers, and thinks about spending the day in just his boxers. He reconsiders when he finds Sherlock’s purple shirt still over the back of his chair. John runs his fingers over the silk, then slips it on. It won’t button properly, of course, but that doesn’t bother him.

When he heads downstairs, he sees Sherlock’s had a similar idea, as he’s sprawled limply on the sofa in pyjama bottoms and John’s stripy jumper, one arm dangling over the side and his other covering his eyes. His dark hair’s a mess, tufted and ruffled as though he hadn’t even bothered to comb it after he’d showered and had let it dry that way. 

“No product today?” John teases as he heads into the kitchen to put the kettle on.

Sherlock lowers his arm and lifts his head briefly to glare at him before letting it flop back onto the sofa. “Tea?”

“Already making you some,” John replies. 

After the tea’s done, he brings two mugs to the living room, nudging Sherlock’s shoulder slightly with his knee. “Budge up,” John says. 

Sherlock does, grabbing the pillow under his head and sitting up just long enough for John to sit down. Then he drops the pillow in John’s lap and rests his head back on it. 

John chuckles and sets Sherlock’s mug on the coffee table. “Told you that you’d had enough to drink.”

Sherlock groans. “Yes, well, if your colleagues weren’t so frightfully dull, I wouldn’t have had to resort to sipping eggnog politely to look interested.” 

John takes a gulp of his own tea, then sets it down as well. “Thank you,” he tells Sherlock. 

“For what?” Sherlock asks. 

“I know you didn’t really want to go, but you went because I asked you to. So, thank you. I appreciate it,” John says. 

“Does your appreciation extend to doing something to rid me of this headache?” Sherlock asks. 

“Hmm. Let’s see if this helps,” John says, setting his fingertips against Sherlock’s scalp and massaging in gentle, soothing patterns. 

Sherlock’s eyes slip shut. 

They’re still sitting that way when a knock comes at their door, Sherlock not-sleeping-but-not-awake and John watching telly while absently running his fingers through Sherlock’s hair. 

“It’s open, Mrs. Hudson,” John calls. 

The door opens, but it isn’t Mrs. Hudson. Lestrade walks in, Anderson close behind him. 

“Lestrade?” John asks. “Do you-”

But Sherlock’s already up and moving with an energy he hasn’t shown all day, darting upstairs. 

“Sherlock!” John yells after him, then sighs and gets up. 

“Sorry to interrupt your day in, doctor,” Lestrade says. 

It’s only then that John remembers that he’s not wearing more than his pants and Sherlock’s purple shirt. He glances down at what he’s got on instinctively, then looks back up. “This isn’t what it looks like.”

“Of course not,” Anderson agrees with a smirk. “Do you two often wear each other’s clothes, then?”

“We have a barter system,” John protests. He grabs the dressing gown hanging over the back of his chair, realizes that it’s Sherlock’s and won’t help his case at all, then gives up and puts it on anyway. “Do you need him for something? This isn’t another drugs bust, is it?”

“No,” Lestrade says. “Or at least, we’re hoping it’s not.”

“Speak for yourself,” Anderson mutters. 

Lestrade ignores him. “Depends on how childish he wants to be.”

“Considering he’s currently hiding upstairs, I’d say very,” John says, then yells, “Sherlock! Get down here!”

As if waiting to make his appearance, Sherlock pads down the stairs, carrying a handful of folders. “I was not _hiding_ , John,” he says with a scowl. “I was merely retrieving what the good detective was looking for.” 

He shoves the folders at Lestrade, and John’s eyes follow them, trying to get a closer look.

“Are those – unsolved case files?” John asks. 

“Yes, and they are the property of the police, Sherlock, I’ve let it go the first few times, but if you do it again, I _will_ arrest you,” Lestrade says. 

“Consider me suitably chastised and well aware of the future consequences of my actions,” Sherlock says, sounding bored. “Now you lot can be on your way.”

Lestrade sighs. “I want the copies you’ve made of them, too.”

Sherlock’s bored expression fades, turning into something of a pout. “ _Fine_ ,” he mutters, going over to the coffee table and leaning down to riffle through some of the papers on it.

“I mean it, Sherlock, you _can’t_ -” Lestrade says, but John stops paying attention. 

Sherlock’s wearing something around his neck, made obvious when he leaned over and it swung free. It’s metal, light glints off it as it hangs in the air, and, now that John’s noticed it, even when Sherlock straightens and it settles back against Sherlock’s chest. 

It’s John’s military ID tags. 

Anger fills John, sharp and deep. He’d _told_ Sherlock his army things were off-limits, and John hadn’t touched that bloody coat, Sherlock has _no right_ to be wearing them. John should have known Sherlock would have no respect for the rules John’d made, even when they were for a system that’d been Sherlock’s damn idea in the first place. 

He leaves without saying anything, because he doesn’t trust himself _to_ say anything, or to remain downstairs and wait until the police have left before shouting at Sherlock. The door to John’s room is open, and there’s a box sitting on his bed. A box that’s normally tucked safely away in the bottom drawer of his desk. 

John sits on his bed and pulls the box into his lap. Everything else is still nearly stored in there, pictures, bits of metal and ribbon, other ID tags. The only empty place is where _his_ tags used to be. Should be, as opposed to where they are now, around the neck of a great idiot. Anyone else would see that their flatmate’s got a box stowed away, doesn’t talk about it, hardly ever takes it out, never wears anything inside, and would go, “All right, probably off limits.” But Sherlock, oh, no, Sherlock sees all that and goes, “obviously it’s perfectly acceptable to raid the contents of this and wear whatever I want around the flat when we’ve got company over.” 

Which is exactly the kind of thought that had made him leave, because thinking of that makes him want to tell Sherlock that he’s wondering at the way his mind works again, and this time _not_ because he loves it, but because he wants to know how Sherlock can be so hurtfully ignorant. And that’s why John’s upstairs. He’s angry enough that he wants to be _cruel_ , and that means he’s upset at more than just Sherlock disregarding a rule of their ridiculous barter system. 

He just doesn’t know _what_. And even if he suspects, just a little, it’s definitely not something he wants to explore. So he hides upstairs, until vicious anger has faded into just anger, until the thought of Sherlock walking around downstairs with John’s tags around his neck doesn’t cause a confusing, twisted knot in John’s chest. 

When he finally goes back downstairs, Lestrade and Anderson are gone. Sherlock is back on the couch, almost exactly as he’d been before they came. Except his head isn’t in John’s lap, and John’s tags are resting against the stripy jumper on Sherlock’s chest. 

“We’ve missed the ending to whatever it is you had us watching,” Sherlock says. “I think they timed it that way.”

John doesn’t respond to that. Instead he says, “You’re wearing my tags.” 

“Mmm, yes, I thought they would do nicely,” Sherlock says. “You’d already gone the traditional route with my shirt and your pants, that was fortunate, and the dressing gown was a nice touch, well done. I couldn’t merely copy you, obviously, and they’d already seen I was wearing pyjama bottoms.” 

John blinks, completely unable to follow that. He ends up saying again, “You’re wearing my tags.”

“Your tags for my dressing gown,” Sherlock says absently. “They’ve been gone almost ten minutes; you needn’t have stayed up there so long.” 

“I wasn’t up there because of them,” John snaps. 

Sherlock rolls on his side so he’s facing John. “You’re angry at _me_.” He actually seems surprised. “Why?”

Of course. Of course Sherlock has absolutely no idea, and yes, John’s ignoring that he doesn’t – or doesn’t want to – either.

“You’re _wearing_ my _tags_ , Sherlock,” John says, like if he just keeps saying it, Sherlock will _get_ it. Which he knows is ridiculous, but-

“You’ve said that three times. I find it unnecessary and irritating when someone repeats himself so often,” Sherlock says, eyes narrowed. 

Yup. Ridiculous. “Yeah, well, _I_ find it unnecessary and irritating when someone breaks the one rule of his own bloody idea.”

Sherlock frowns. “I haven’t done anything wrong,” he says defensively. 

“My tags, Sherlock,” John says. “Yes, I know, I’m repeating myself, but as you’re refusing to _get it_ , it seems to be my only option. I haven’t touched your damn coat, so why are you wearing my tags?” 

Sherlock reaches up, closing his fingers loosely around the tags. “You said it was your uniform and camouflage that were off limits,” he says quietly. 

“No, _you_ said that. I said, ‘my army things.’ I would’ve thought a genius could figure out that ID tags are part of army things. Then again, I would’ve thought a genius would be able to discern that a box at the bottom of my desk drawers is off limits, but apparently not,” John says. 

Sherlock’s grip tightens, blocking the metal entirely from view. “You never wear them. I thought that meant you wouldn’t mind if I did.”

“I don’t _wear_ them because-” he cuts off, not entirely sure what he was going to say, but knowing it wouldn’t have been anything he wanted to come out. “Just because I don’t wear them doesn’t mean it’s okay for you to.”

But Sherlock notices his aborted sentence and the emotion behind it (of course he does, it’s _Sherlock_ ), and he sits up, eyes focused on John intensely. “You aren’t just angry with me for wearing your off-limits item.”

“Shut up,” John says. 

“Because what, John?” Sherlock asks. 

“I don’t want to talk about it,” John replies. 

Sherlock leans forward slightly. “Why not?”

“Because – because we’re not talking about me, Sherlock, we’re talking about you and your rule-breaking,” John tells him. “I want to know _why_ you’re wearing my tags.” 

Sherlock’s open, interested expression shuts down. 

“You were trying to throw me off, weren’t you?” John pauses, then asks quietly, “ _Why_?”

“As I’ve said before, you’d already gone the traditional route,” Sherlock says stiffly, not meeting his eyes. “I didn’t have that option. I had to choose another method of demonstration.” 

“Demonstration of _what_?” John asks, frustrated. “What does that mean?” 

“It means we belong together, to each other, John, that’s what it, what _all_ of it _means_.” Sherlock tugs on the jumper and makes a gesture than includes all of John. Then his voice turns quiet, almost hurt. “I thought you knew that.” 

John stares at him, frustration and anger fading away to something that’s not quite sadness and something that’s much more than affection. “Sherlock,” he says softly, then clears his throat. “We’re not dating.” 

“I know that,” Sherlock snaps. 

But he’d flinched, just a tiny bit, and John regrets saying it, even if it is true. 

“Can’t we belong to each other without being in a relationship?” Sherlock asks hesitantly. 

“Well, yeah, but-” John pauses. He remembers Sherlock’s shy smile yesterday, when John’d said “let them talk,” and he takes the plunge. “But it’s more fun if we are.”

Sherlock’s eyes snap to his face, lock on to his. “John,” he whispers. 

“We don’t have to be, if you don’t want to,” John says. “But I’d like to give it a try.” 

There’s a brief pause, then Sherlock smiles at him. “Come here.”

John obeys, sitting next to Sherlock, and then Sherlock’s lips are pressed against his. 

They kiss lazily on the sofa, not as a precursor to anything, just because they _can_. When they stop, Sherlock curls up on the sofa, head in John’s lap, and John realizes that almost _nothing_ has changed, except now Sherlock’s hand is on his knee and John’s lips are kiss-swollen. 

“You realize this means I get to wear your coat now, right?” John asks as he runs his fingers through Sherlock’s hair. “If you get to break the rules, I get to as well.”

Sherlock considers that, then nods. “That’s acceptable now.” 

John blinks. “Why now?”

“You’ve worn it once before, do you remember?” Sherlock asks, twisting to look at him.

This is news to John. He shakes his head. 

“I didn’t think so; you were only half aware at the time. It was after you’d been pushed into the Thames. It was freezing, you needed dry clothes, I gave you my coat until the paramedics arrived. You looked – well, if you hadn’t been so dazed, I would have jumped you on the spot. I set the coat off limits because I suspected if you wore it again with your senses intact, I might not be able to restrain myself.” Sherlock smiles. “I assume, based on our activities during the past fifteen minutes, that I no longer need to worry about you being opposed to that.”

John swallows. “No, that’s really not a worry.” 

In fact, it gives him an idea. And later that night, when Sherlock’s gone into the kitchen to check on some experiment he’s got going in the fridge, John takes off the dressing gown and hangs it up. After a moment’s consideration, he hangs up the purple shirt as well and slips on Sherlock’s coat. It’s ridiculously long and tight in the shoulders, but actually quite comfortable. 

He waits silently, and it’s well worth it when Sherlock walks back into the living room and stops, mid-stride, at seeing him.

“You’re wearing my coat,” Sherlock says. 

“Looks like,” John agrees. 

And Sherlock does jump him, but it’s John that pushes them both onto the sofa. 

John pulls Sherlock’s pyjamas down to his knees, freeing his half-hard cock, and pauses just long enough to meet Sherlock’s eyes before he takes it into his mouth. John licks and sucks, teasing it quickly to full arousal. But then Sherlock’s pulling his head away, and his cock slides out of John’s mouth with a soft, wet plop. Sherlock kisses him again, his hands tugging at the waistband of John’s boxers, and John shifts a bit to get them off. 

Sherlock kicks free of his pyjama bottoms, slides his hands down John’s sides, rests them on his hips. 

John slips his own hands under the jumper Sherlock’s wearing. He pushes it up, fingers touching every inch of skin as it’s revealed to him. John gets the front of the jumper over Sherlock’s head, bunched up behind his neck, but then Sherlock wraps his fingers around John’s cock and _strokes_ , and getting the jumper removed is forgotten. 

John pants against Sherlock’s mouth, hips thrusting slightly no matter how he tries to still them. He pulls back a bit to look at Sherlock, and sees his tags. 

Sherlock’s still wearing them. 

John touches Sherlock’s chest, right next to where the tags are resting against more bare skin, and right now, John doesn’t mind. 

He kisses his way down Sherlock’s chest, his stomach, then slides his lips over Sherlock’s cock once more. John goes slowly this time, tracing veins with his tongue, teasing at the foreskin, alternating between barely there friction and hard, wet suction. 

John watches Sherlock the whole time, the way his eyes squeeze shut for brief periods of time before he opens them again, watching John watching him, the way he tosses his head back when John does something particularly wicked with his tongue, the way his chest hitches and his breath comes in short, quiet gasps. 

When Sherlock comes, he silently, completely falls apart. John swallows and pulls off him, running his hand across Sherlock’s sweat-soaked chest while he watches Sherlock put himself back together again. He considers trying not to feel utterly grateful and absolutely brilliant that he’s the one who got to see- who was the cause of – Sherlock undone, but writes it off as a failure before even trying. 

Instead, John wraps his fingers around his own cock, but he only gets a few strokes in before Sherlock bats his hand away and takes John in hand himself. 

John’s own climax is louder than Sherlock’s, but not much more controlled. 

He collapses half on top of Sherlock when he’s done. It’s too warm, considering John’s still wearing Sherlock’s coat and Sherlock himself is over-heated underneath him, but John doesn’t care. 

John strokes his hand over Sherlock’s arm, smoothing across the fabric, before he slips his fingers under the bunched up stripy jumper to rest on Sherlock’s shoulder. 

“Do you know why I really said it was fine when you first wore my jumper?” John asks. 

“Why?” Sherlock says. 

“Because I liked you in it. You’re right, it does say we belong to each other.” John shakes his head. “Only you could make my jumpers look sexy.” 

Sherlock slides his hand under his coat, fingers playing over John’s hip. “I disagree. You quite frequently make your jumpers look ‘sexy.’”

John laughs, and falls silent. 

They stay like that for awhile, until Sherlock breaks the silence by asking, “Why don’t you wear your tags?”

John tenses. “I said I don’t want to talk about it, and I meant it. I _especially_ don’t want to talk about it now.”

“I deserve to know,” Sherlock insists. “Why you were so angry at me. How can I avoid your anger if I don’t know the cause of it?”

“I don’t even know the cause of it,” John tells him. “It doesn’t matter, I’m not angry any more. Just let it go, Sherlock, please.” 

“It’s not just because they’re part of your army things, that much is obvious,” Sherlock says. “You were angry because I was wearing them, because you never do, but you don’t want to tell me the reason you don’t. It’s not just you not wearing them, it’s when someone else wears them, or is it just when I-”

“It’s because you just _took_ them, Sherlock! You just walked around wearing them like they belong around your neck, when they don’t even belong around mine.” John realizes what he’s said a second after he blurts it out. He closes his eyes and admits softly, “They don’t. Not anymore.” 

There’s silence for a moment, then the soft clink of metal, and then a slight weight against John’s chest. 

John opens his eyes, startled. Sherlock’s taken his tags off and put them around John’s own neck. 

“You are a soldier, and a hero. There is absolutely nothing that can or ever will change that, John, not even you,” Sherlock says. “I suggest you get used to the idea.” 

John just stares, because he doesn’t know what to say to that. Finally he murmurs, “I thought you didn’t believe heroes existed.” 

“That was before I got to know you,” Sherlock replies. 

John reaches up, slowly curling his fingers around his tags. After awhile, he says, “Suppose this means I should give you your coat back.” 

“I’m still wearing your jumper,” Sherlock says, adjusting it so that it’s on properly. “I’ll consider that an acceptable trade.” 

“Our barter system’s still on, then?” John asks. 

Sherlock grins at him. “Absolutely.” He rolls off the sofa, picking up John’s boxers and pulling them on. “Coffee?” 

“Hmm,” John says, too busy staring to register what Sherlock’s asked. “Oh, yes, sure.”

“Excellent,” Sherlock says. “Make enough for several cups, I’m sure we’ll both be up quite late tonight.” 

He saunters into the kitchen, leaving John to scramble into Sherlock’s pyjama bottoms. John does take off the coat, because between it and the too-long pyjamas, he’d have a hell of a time manoeuvring. It’s still slightly awkward making coffee, even with the pyjama legs rolled up a bit, but John couldn’t care less. 

Sherlock’s leaning up against the kitchen table, hair mussed from sex rather than sleep, wearing John’s jumper and pants. They both smile every time they catch each other looking, which is every few seconds or so. 

John’s happier than he can ever remember being.

**Author's Note:**

> This [lovely art](http://krusca.deviantart.com/art/Sherlock-Barter-System-288123868) of Sherlock in John's tags and John in Sherlock's coat was done by krusca over on Deviant Art!
> 
> This fic is also available in [PDF, ePub, or MOBI (Kindle)](http://ithindiniel.tumblr.com/post/51810044830/barter-system) courtesy of Ithindiniel, and in [audio form](http://vertiga.tumblr.com/post/30766975094/barter-system-a-sherlock-fanfic-written-by-anon) courtesy of Vertiga!

**Works inspired by this one:**

  * [[Podfic] Barter System](https://archiveofourown.org/works/1014052) by [Vertiga](https://archiveofourown.org/users/Vertiga/pseuds/Vertiga)




End file.
